1. Field of the Invention
The present invention relates to a free wheel hub clutch device. More particularly, the present invention relates to a free wheel hub assembly disposed between an axle which is rotationally driven during only a four-wheel driving operation of a four-wheel drive car and to a wheel hub that the free wheel hub clutch device of the present invention connects to the axle permitting propagation of a driving force therebetween.
2. Description of the Prior Art
A conventional free wheel hub clutch device related to the present invention is disclosed, for instance, in the specification of Japanese Patent Laid-Open No. 51620/1984. This type of free wheel hub clutch device includes a cylindrical body fixed to an external end of a wheel rib rotatably fitted to an external end of an axle tube. An inner sleeve is linked to an external end projection of the axle inserted through the axle tube within the cylindrical body so as to permit propagation of a driving force. A clutch member is attached to the cylindrical body so that it is axially slidable and a handle is rotatably fitted to the cylindrical body. A cam follower is provided for causing the clutch member to engage with the inner sleeve by making the clutch member slide in the axial direction while interlocking with the handle. The arrangement is such that the propagation of the driving force becomes possible by manually turning the handle in order to cause the clutch member to mesh with the inner sleeve.
So far as the above-described prior art device is concerned, the handle is manually operated at the wheel to effect power conversion from a two-wheel driving system to a four-wheel driving system. Hence, it is required for the manipulator to go outside the vehicle. This requirement causes an inconvenience both to the operator on the occasion of terrible conditions both of weather and of the road.
Furthermore, the aforementioned conventional free wheel hub clutch device which employs a motor is attended with the following problems. Grease which is fully charged in a wheel bearing flows out therefrom and adheres to a slip ring serving as an electrical charging member for the motor and to a brush, thereby forming oil films. As a result, the motor is hindered from being charged with electricity, and further, sparks are generated to such an extent that the slip ring is damaged.